Question

The mass number of the sulphur atom is ? (Atomic number = 16 and number of neutrons = 16)
A. 18
B. 32
C. 24
D. 16

Answer 1

Hint:The mass number is calculated by adding the number of protons present in the nucleus of an atom and the number of neutrons present in the nucleus of the atom. The atomic number of the atom represents the number of protons present in the atom.

Complete step by step answer:
Given,
Atomic number is 16
Number of neutrons is 16.
The atom is composed of positive charge protons, negative charge electrons and neutral charge neutrons. The sum of the mass number and atomic number of an atom gives the total number of subatomic particles present in the atom.
The mass number is the mass of an atom's nucleus in atomic mass units.
The atomic number of the atom is the total number of protons present in the nucleus of the atom. The atomic number is denoted by Z.
The mass number is equal to the total number of protons and neutrons. The mass number is denoted by A.
Atomic number = number of protons = 16
Number of neutrons = 16
Mass number = number of protons + number of neutrons
Substitute the values in the above equation.
$\Rightarrow Mass\;number = 16 + 16$
$\Rightarrow Mass\;number = 32$
Thus, the mass number of sulphur is 32.
Therefore, the correct option is B.

Note:
Atomic number and mass number are always in whole numbers as they are obtained from counting the total number of protons, neutrons and electrons. As both protons and neutrons are present in the nucleus they are combined and named as nucleons.